Multiscale- and Multiphysics-Based Approach for Predicting Manufacturability, CAD Conformity, and Residual Stresses in Powder Bed Fusion Parts

This paper was produced for the 2019 NAFEMS World Congress in Quebec Canada

Resource Abstract

Additive Manufacturing has developed rapidly during the last decade, it has demonstrated significant design flexibility - particularly for customized products. It is also considered, from environmental perspective, as a preferable option to most of the conventional manufacturing processes. Both can be realised through improved design freedom, reduced material waste, reduced energy consumption, and clear saving in cost and CO2 footprint. It is well known by now that the term “Additive Manufacturing” is used loosely to address several families of processes. This paper will consider only the Powder Bed Fusion (PBF) family.

All PBF processes share a set of basic principles – mainly, the use of a heat source (either a laser or electron beam) to induce a controlled fusion-zone between powder particles, and a method to deposit and smooth the powder distribution layer by layer. It is well proved by now that the energy used during the process often leads to distortions during printing that may interrupt the deposition process. The final shape of the printed component may also deviate significantly from design and residual stresses may lead to cracking of the component.

Many studies, both experimental and numerical, have been carried out to analyse how process parameters such as heat source power, scan speed, and scan strategy affect the final shape of the component as well as its mechanical properties. For such a study to be comprehensive it must address various physics involved at several levels - ranging from the 10s - 100s of microns (the melt-pool or powder level) through to 10s of mm (the hatch level), through to full components up to 100s of mm (the macro level). This paper presents a global multiscale- and multiphysics-based approach adopted by ESI Group while developing its own solution to tackle this problem for industrial applications.

The paper, first, presents a quick overview of the PBF process and associated challenges & opportunities; then introduces the major components of an Integrated Computational Materials Engineering (ICME) platform - including tools for modelling: powder melting and solidification, part distortion, and powder spreading. It then discusses three validation cases, each associated with one of the modules above; all were carried out jointly by the authors as part of ESI academic collaboration programme with Swansea University.

Document Details

AuthorSaid. R
Date 18th June 2019
OrganisationESI UK Limited


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